1. Field of the Invention
The invention is directed to an improved flow pump, in particular for pumping fuel from a tank to an internal combustion engine of a motor vehicle.
2. Description of the Prior Art
One flow pump of the type with which this invention is concerned is known from German Patent Disclosure DE 43 40 011 A1. This flow pump has an impeller driven to revolve in a pump chamber and on at least one face end has a ring of blades spaced apart from one another in the circumferential direction. The blades end at the face end of the impeller and between them define blade chambers, which have a radially inner blade chamber bottom. In the pump chamber, at least one feed conduit is embodied in the form of a split ring, cooperating with the blades of the impeller. An intake opening discharging into the feed conduit is embodied in a pump chamber wall that defines the pump chamber in the direction of the pivot axis of the impeller. At least one outlet opening also discharges into the pump chamber. It has been demonstrated that in this known flow pump, when hot fuel is pumped, the supply quantity drops sharply because of the development of vapor bubbles. The development of vapor bubbles occurs above all in the region of low pressures and thus in the region of the intake opening. At that location, the embodiment of the feed conduit and of the impeller in the known flow pump is not optimal.